1. Field of the Invention
The present invention relates to a motor-driven single-lens reflex camera and to a motor-driven single-lens reflex camera for self-feeding film cartridge, in which a single motor drives both a mirror/shutter system and a film feeding system.
2. Description of the Related Art
In regard to a motor-driven single-lens reflex camera constituting a motor to control an up/down operation of mirror and to carry out a shutter charge by driving a mirror/shutter driving system, and another motor to feed (wind) and rewind a film by driving a film feeding system, although it is possible to increase the speed of feeding of the film after exposure (namely, the frame feed speed), it is still difficult to minimize the size of camera because a larger space is required to mount two motors thereon, which further results in higher cost. Accordingly, there has been suggested a single-motor type of single-lens reflex camera, which drives both the mirror/shutter driving system and the film feeding system by the single motor, so that the minimumizing of space and cost of the camera can be accomplished. There are such type of cameras in the related art, for example, in which a film is fed by a sprocket capable of feeding by a regular angle, or in which a film is fed by driving a spool (Japanese unexamined patent publication No.1-202731, duly published after examination under No.8-10313). However, the related art makes the single motor carry out a plurality of tasks, thus transmission systems thereof may become complicated.
The camera of the above-mentioned related art carries out an up/down operation of a mirror and a shutter charge by rotation of a motor in one direction (forward direction), and a feed and a rewind of film by rotation of the motor in the opposite direction (reverse direction). In this structure, during a release operation, the motor is initially stopped after an operation of the mirror/shutter system, then the film is fed by the reverse rotation of the motor. Therefore the frame feed speed (the speed of film feed per frame) becomes slower, hence the camera is not suitable for sequential photographing.
In addition, although the single-motor type of single-lens reflex camera may minimize the size and cost of the camera, there are limitations to the various operation modes and faster driving speed due to complicated switching of driving directions. For example, it is difficult to operate at multiple exposures, which is different from ordinary photographing operations.
There is a camera complying with a new photographic system called "Advanced Photo System" which uses a self-feeding film cartridge. Under such a new system, since there are novel operations during loading of the film such as "film thrust" (setting the first film-frame) or "rewind write, (rewriting of magnetic data), that are not performed in regard to the conventional camera using 35 mm-type of film, it is difficult to control these novel operations by a single-motor type of single-lens reflex camera of the related art.